Added way to retrieve shop info by clicking it with a specific item

Closes #104

src/main/java/de/epiceric/shopchest/config/Config.java

@@ -4,7 +4,9 @@ import de.epiceric.shopchest.ShopChest;
 import de.epiceric.shopchest.event.ShopUpdateEvent;
 import de.epiceric.shopchest.language.LanguageUtils;
 import de.epiceric.shopchest.sql.Database;
+import de.epiceric.shopchest.utils.ItemUtils;
 import org.bukkit.configuration.InvalidConfigurationException;
+import org.bukkit.inventory.ItemStack;
 
 import java.io.BufferedReader;
 import java.io.File;
@@ -25,6 +27,9 @@ public class Config {
     /** The quality of hologram and item updating (performance saving, or better quality) **/
     public ShopUpdateEvent.UpdateQuality update_quality;
 
+    /** The item with which a player can click a shop to retrieve information **/
+    public ItemStack shop_info_item;
+
     /** The default value for the custom WorldGuard flag 'create-shop' **/
     public boolean wg_allow_create_shop_default;
 
@@ -334,6 +339,7 @@ public class Config {
         plugin.reloadConfig();
 
         update_quality = ShopUpdateEvent.UpdateQuality.valueOf(plugin.getConfig().getString("update-quality"));
+        shop_info_item = ItemUtils.getItemStack(plugin.getConfig().getString("shop-info-item"));
         wg_allow_create_shop_default = plugin.getConfig().getBoolean("worldguard-default-flag-values.create-shop");
         wg_allow_use_admin_shop_default = plugin.getConfig().getBoolean("worldguard-default-flag-values.use-admin-shop");
         wg_allow_use_shop_default = plugin.getConfig().getBoolean("worldguard-default-flag-values.use-shop");

src/main/java/de/epiceric/shopchest/listeners/ShopInteractListener.java

@@ -394,12 +394,29 @@ public class ShopInteractListener implements Listener {
                         }
                     }
                 } else {
-                    if (shopUtils.isShop(b.getLocation())) {
+                    Shop shop = shopUtils.getShop(b.getLocation());
-                        Shop shop = shopUtils.getShop(b.getLocation());
+                    if (shop != null) {
-
                         if (e.getAction() == Action.LEFT_CLICK_BLOCK && p.isSneaking() && Utils.hasAxeInHand(p)) {
                             return;
                         }
+                        ItemStack infoItem = config.shop_info_item;
+                        if (infoItem != null) {
+                            if (e.getAction() == Action.RIGHT_CLICK_BLOCK || e.getAction() == Action.LEFT_CLICK_BLOCK) {
+                                ItemStack item = Utils.getItemInMainHand(p);
+                                if (item == null || !(infoItem.getType() == item.getType() && infoItem.getDurability() == item.getDurability())) {
+                                    item = Utils.getItemInMainHand(p);
+                                    if (item != null && infoItem.getType() == item.getType() && infoItem.getDurability() == item.getDurability()) {
+                                        e.setCancelled(true);
+                                        info(p, shop);
+                                        return;
+                                    }
+                                } else {
+                                    e.setCancelled(true);
+                                    info(p, shop);
+                                    return;
+                                }
+                            }
+                        }
 
                         if (e.getAction() == Action.RIGHT_CLICK_BLOCK && p.getUniqueId().equals(shop.getVendor().getUniqueId()) && shop.getShopType() != ShopType.ADMIN) {
                             return;

src/main/java/de/epiceric/shopchest/utils/ItemUtils.java

@@ -74,6 +74,8 @@ public class ItemUtils {
      * @return The de-serialized ItemStack or {@code null} if the serialized item is invalid
      */
     public static ItemStack getItemStack(String item) {
+        if (item.trim().isEmpty()) return null;
+
         if (item.contains(":")) {
             Material mat = Material.getMaterial(item.split(":")[0]);
             if (mat == null) return null;

src/main/resources/config.yml

@@ -23,6 +23,10 @@ show-shop-items: true
 # may lead to TPS loss.
 update-quality: NORMAL
 
+# Set the item with which a player can click a shop to retrieve information.
+# You can set this to an empty string to disable this feature.
+shop-info-item: "STICK"
+
 # Set whether interaction with the hologram should be enabled.
 # If set to true, a player can do the exact same thing with the
 # hologram, as with the chest. You can even open the chest if you